Chart drive mechanism



Dec. 8, 1953 Filed April 22, 1949 J. B. M GAY ET AL CHART DRIVE MECHANISM 2 Sheets-Sheet l INVENTORS 29 E1 Nicholson John B. McGay id M w Attorneys Dec. 8, 1953 J, B. MGGAY ET AL 2,66

CHART DRIVE MECHANISM Filed April 22, 1949 2 Sheets-Sheet 2 INVENTORS George E Nicholson John B Mcay Attorneys Patented Dec. 8, 1953 CHART. PRI ME H NI M John. B. McGay and-George, E; Nicholson, Tulsa,

O la, as i nors. ofi we eg st G lmor 9 rrqr tipi e viqrk Application April 22, 1949, Serial No. 829,03? sciaims. (01. 1255- 8) This invention relates to operating mechanism.

for meter charts or the like.andihas fonits eral object and purposetoprovide a highlyconipact and novel assembly of. the drivemechanism for the. chart shaft or hub with novel means for.

removably mounting the assembly upon an instrument panel where space for the larger.

standard chart drives is not available.

It is another object of the invention toprovidedrive mechanism for the.abovepurposeembody ing. a. spring energized clock unit together-with an interchangeable escapement unit and meansfor removably mounting the escapementunit. in operatively assembled relation with the clock unit so that, byv the use of easily interchangeable.

escapement units, the rate. of rotation-of the chartby the clock unit may be selected.

It is a further object of the invention to provide means for detachably locking. the clock andescapement unit upona mounting'platewith the escapement unit having. means, coasting. with.

parts of said locking means to removably retainsaid escapement unit in operatively assembledrelation with the clock unit.

It is an additional object of the invention to provide an operating mechanism for meterchartsas above characterized, in. which the energizing spring for the clock unit. is directly connected:

with the chart shaft orarbor and is wound. by rotation of said shaft.

A further object of the invention, resides inthev provision of a novel ratchet gear assembly.

whereby, in the rotation. of thechart shaft to. wind the clock sprin torquestresses will not be.

transmitted to the mechanism of the escapement uni It is another object of theinvention to provide. a clock case of novel constructionv withmeans for.- reversibly mounting the clock spring therein so.

that the chart shaft may be driven. thereby in. either clockwise or anti-clockwise direction.

Still another object of the. invention resides in. the provision of amounting plate-of very simple. construction provided with novel: means to.

resiliently coact with a locking. member carried by the drive assembly to. detachably secure. said. assembly in rigidly supported position. uponsaid mounting plate.

With theabove and other objects in. View, the

invention comprises the improved operating mechanism for meter charts or. the like, and the,

construction and relative arrangementof its. SeYr'.

eral parts as will hereinafter be morefully de.-.

scribed, illustrated in the accompanying drawings and subsequently incorporated in the. sub.-.

joined claims.

In the drawings. wherein we have disclosed one. simple. and practical embodiment of the inven.-

tion and in which. similar reference characters designate corresponding. parts throughout the.

several views.

Figure l is a front elevationwith certain of the.

partsbrokenaway to show theprimary elements of. the clock mechanism;

Figurev 2 is-arear elevation; Figure 3 is. a vertical sectionalview takensub-rv stantiallyontheline 3 3.of Figurel, and show: ing the. drive. assembly detachably locked upon.

the. mounting plate within the instrument. case;

Eigure l is a detailverticalsection takenlsubstantially. on the line 4-4.. of Figure, 1;

Figure 5 is an elevation of the parts. ofthey ratchet gear assembly;

Figure 6 isa planview of. the ratchet plate;

Figure. 7 is a detail horizontal section taken.

substantially on the line T'|. of Figure 3.;'

Figure. 8 is a. detail. frontv side. elevation of-the. escapement unit; and.

Figure 9 is a. rear sideelevation ofthe mount-. ing plate.

partment I6.

In the upper portion of the case body wall and;

at opposite sides thereof axially extending pins l8 are .secured and-.in the central bottom portion,

of said walla similar. pin 20 is secured. Opposite end portions of these pins are threaded andiproject-beyond the edge faces of the case, Wall. In

each. edge facev of this wall below the pins L8: suitable dowel pin receiving recesses 22 are,-

formed.

The open. side of-the. springv compartment [4; of. the clock case is closed by. the front cover plate. 2t. while the open side of thev gear compartmentv It:. is closed by similar rearcover plate. 26. These lates carry dowel pins as indicated at 21. fitting within. the recesses 22 and suitably'spaced openings. registering with the threaded ends of th pins. [8 and. 20. Upon thefront endsof these pins the cap screws 28 arethreaded to securely clamp,

the front cover plate 24. against the edge. face of.- the case body Wall. Lockingstuds 30 are threaded. upon the rear ends of the pins l3 and a lockingstud 3-2 of somewhat different form is. also.

threaded upon the rear end of. pin 20. to tightly clamp the rear coverplate 26 against the. case.

body wall. The construction and purpose of these locking studs will be hereinafter explained in further detail.

In the front plate 24 above the center thereof a bearing bushing 34 for the chart shaft or arbor 66 is suitably secured. The rear reduced end of this shaft is journalled in a bearing bushing 33 mounted in the rear cover plate 26. Upon an intermediate section of shaft a sleeve M! is keyed or otherwise non-rotatably fixed and extends rearwardly through an opening in the partition plate i2. The rear end of this sleeve with in the compartment [6 is of reduced diameter and upon the same a large diameter spur gear 42 is suitably fixed. At its forward end the sleeve is formed with a spring attaching lug 4 projecting radially therefrom approximately midway between the front cover plate E i and partition plate if. A spacing collar 43 surrounds the shaft or arbor 3 5 between the forward end of r sleeve 41.! and the rear end of bearing bushing 34.

Below the shaft 355 and out of vertical alignment therewith a shaft at is journalled at its opposite ends for rotation in bearing members 5i) and 52 suitably mounted respectively in the par-- tition plate 12 and rear cover plate 26. A pinion 54 is integrally formed with the forward end portion of this shaft and is in constant mesh with the chart shaft gear 42. At the rear side of this pinion flange 55 is integrally formed therewith and in spaced relation to this fiange teeth or splines 53 are formed on the pinion shaft. tween flange 56 and the teeth 58 a ratchet gear 60 is loosely mounted for free rotation on the pinion shaft.

A ratchet plate 52 of spring metal, as shown in Figure 6, is centrally provided with an open-'- ing the edge of which is formed with teeth corresponding to the teeth 58 on shaft 43 and with which they are adapted to interlock to thus nonrotatably secure the ratchet plate to said shaft. This plate at diametrically opposite points is formed with the spring tongues dd projected in the same direction out of the plane of said plate and extending circumferentially thereof in relatively opposite directions. The ratchet gear 60 is formed with hub and rim portions integrally con nected by the spaced radial spokes 66 with which the free ends of the spring tongues 84 on the ratchet plate are adapted to coact to thus connect gear 60 with the ratchet plate for rotation as a unit in one direction with the shaft 48.

In vertical alignment with the chart shaft or arbor 36 and coaxially of the casing compartment IS, a shaft i0 is rotatably journalled at its opposite ends in bearing members l2 and l l respectively mounted in the partition plate l2 and rear cover plate 2% This shaft is provided with an integrally formed pinion i6 which is in constant mesh with the ratchet gear Gt). The rear end portion of this shaft is formed with a rectangular axially extending bore to receive one end of a square coupling shaft '13 the other end of which projects beyond the rear face of cover plate 26.

The spiral clock spring fl is housed within the compartment 14 of the case. This spring at its inner end is provided with a suitable slot or opening and is hooked over the radially projecting lug 44 on the sleeve 40 fixed to the chart shaft or arbor 36. The casing vall at the bottom center thereof is internally formed with an upstand ing boss 19 providing laterally spaced shoulders 80. One end of a longitudinally bowed relatively strong spring leak 82 is engaged at one end with one of the shoulders 86 and extends upwardly therefrom above the center of the case and has bearing contact at its upper end against the cir" cumferential surface of the case wall. To this latter end of the bowed leaf 82 the other or outer end of the clock spring ii is securely riveted as at 84. As shown in the drawing the spring i? is positioned to rotate the chart shaft or arbor in anti-clockwise direction. However, by reversing the position of the spring with the spring ieaf 82 positioned at the opposite side of the vertical center line of the case and in abutting contact with the other of the shoulders the chart shaft or arbor will then be rotated in the clockwise direction as the spring unwinds.

It will be understood that when the spring is so installed simple modifications will made in the gear train and particularly the one-way drive mechanism to permit winding of the spring and transmission of the drive to the escapement mechanism as the spring unwinds.

The action of the clock spring fl and the rate of rotation of the shaft 36 and the chart during a predetermined time period of operation is controlled by an escapement unit generally indicated at 56. By interchangeably coupling properly se lected escapement units with the pinion 16 the same clock mechanism may be used for the operation of differently calibrated one day, seven day or thirty day charts. These escapernent units may be of any approved standard construction. A special escapement unit is employed when it is desired to rapidly rotate the chart for test pur poses. The mechanism is enclosed within a hermetically sealed case 88, and for the purpose of this description, it will suffice to state that this mechanism includes a shaft element journalled in the case axially thereof and having a square bore at one of its ends to receive the square cowpling shaft 18 projecting from the rear side of the clock case.

As shown in Figure 8 of the drawings a rim portion of the case 88 is provided with a plurality of spaced outwardly projecting flanges iii) corresponding in number to the number of locking; studs 36 and 32, each of said flanges having a cam edge and a stop shoulder 94 at one end thereof.

The locking studs 3%] and 32 have cylindrical; end portions 96 provided with threaded bores; which receive the rearwardly projecting threaded ends of the pins I8 and 20. In spaced relation from each cylindrical portion 96 the two studs. 30 are formed with the flanges 98 having flat. outer side faces. The inner side faces of these flanges and the opposed ends of the cylindrical portions 96 of the studs are convergently beveled inwardly to a cylindrical neck portion 500 of relatively small diameter. The lower locking stud 32 is similarly formed with a flange I02 of somewhat greater diameter than the fianges 98 on the studs 30 and with the connecting neck portion I04 between the flange I02 and the cylindrical end portion of the stud.

The studs 30 rearwardly of the flanges 98 are formed with shallow annular grooves I66 and axially tapering terminal portions 108. The lower locking stud 32 at the rear side of flange I02 has a narrow cylindrical portion Ht of substantially the same diameter as the end portion of the stud and outwardly thereof is formed with an annular groove I I2 and a conical or dome shaped terminal head H4.

In the front side Wall of the escapement case axially thereof a guide bushing H6 is secured by nut I [8. In assembling the clock and escape- :ment units the latter is inserted from :the rear between the ,studs .30 and 732 .on :the clock base with the flanges '90 circumferentially positioned betweensaid-studs. V-By relative axial movement, the projecting end .of the .square coupling shaft 1-8 is received .through the guide bushing H8 and into the square .bore of the shaft element of the escapement mechanism, at which time the nut H8 is in substantial contact with the face of the rear cover plate 26 of the clock unit, and the flanges 90 on the escapement case 88 are positioned in substantial alignment with the neck portions I00 and I04 of the locking studs. Upon now slightly rotating the escapement unit, the cam edges '92 of flanges efl'frictionally ride upon the cylindrical surfacesof the neck portions I00 and I 04 of the locking studs until the shoulders 94 on said flangescontact therewith. Theescapement unit is thus securely though releasably retained in operatively assembled relation with the clock unit.

In Figures 3 and 9 of the drawings we have shown means for easily and quickly mounting this chart clock and escapement assembly on an instrument case or removing the same therefrom. In the present instance, we have shown an annular mounting plate I20 which may be provided with suitable adapter means for application to any instrument case. However, in Figure 3 of the drawings this mounting plate is rigidly secured by tion as the pins I8 on the .clock case and the locking studs 30. The upper portions of these openings are of circular form, each having a downwardly extending tapering portion I28. In the lower portion of the plate I20, centrally thereof, a vertical slot or recess I30 is formed the upper end of which opens upon the inner edge of the annular plate.

In spaced relation from the slot I30 at each side thereof vertically disposed strap portions I 32 are punched or struck and project from the plane of said plate at the rear side thereof. Each of these strap portions I32 intermediate of its ends is indented to form a supporting shoulder I34 for the ends of a bowed resilient rod I36 inserted between said strap portions and the rear face of the plate I20. This resilient rod at its center extends across the upper open end of the slot I30 in the mounting plate. The width of the slot is slightly greater than the diameter of the part IIO on the lower locking stud 32 for the clock case.

In mounting the drive assembly upon the plate I20, the case 88 of the escapement unit is fitted within the opening of the annular mounting plate while the tapering terminals I08 of the upper locking studs 30 move rearwardly through the openings I26 in said plate. The conical head H4 on the lower stud 32 in passing through the slot I30 in the mounting plate encounters the resilient locking rod I36 the central portion of which is sprung from its normal position and received in groove II2 of the stud 32 as the rear fiat faces of the flanges 98 and I02 on the studs contact the front face of the mounting plate I20. The downward pressure of rod I36 on stud 32 positions the neck portions I00 of the upper studs 30 in the tapered lower ends I28 of the openings I26 in the mounting plate. Thus in the mounting of the drive assembly it is securely locked in the instrument case at three separate points.

To change the escapement unit, .or for other purposes, the chart drive assembly may beeasily andquickly-dismounted from the instrumentcase by merely lifting the assembly upwardly slightly relative to the mounting plate I20 against the resistance of the resilient locking rod I36 so that the locking studs 30 and .32 may be withdrawn forwardly through the openings in said plate.

The forwardly projecting portion .of theshaft or arbor 3B is tapered as at I38 :to receivea chart holding hub and terminates in a square or poly gonal end portion I40 to which a socket type key may be applied after each operation for the predeterminedtimed period, to rewind thespring H. In this operation pinion 54 and shaft :48 'will be rotated by gear 42 reversely to the chart-driving direction and the spring tongues 64 of ratchet plate 452 fixed to the pinion shaft will ride over the spoke elements 66013 the ratchet gear $0,.and said gear and the .escapement drive pinion 16 .will remain stationary so that no torque stresses will be transmitted to the elements of the escapement mechanism in the winding of the clock spring. Thus the provision of an vadditipnal opening in the front plate v24 of the clock case-t0 receive aspring winding key is avoided. Preferably, for greater ease and facility in the replacement or substitution of charts, without mutilation thereof, a chartholding hub of the type .disclosed :in our applicationSerial No. 65591-6, filed March 21, 1946, is mounted'on the drivin shaft or arbor 36.

From the above description, it will .be seen that the present invention provides a drive mechanism for meter charts or the like which will beiunc- .tionally positive and reliable in operation and comprises the minimum number of compactly assembled parts so that the drive assembly may be readily mounted in an instrument case of relatively small size, where space for the conventional chart drive assembly of larger vdimensions is not available. It will be seen that the clock unit of the drive mechanism as above .described has considerable merit by reason of its extreme simplicity and the fact that the energerizing spring therefor may be .readily mounted and arranged within the clock case to drive the chart in either direction. The interior of the clock case may be hermetically sealed by the application of a suitable sealing medium between the front and rear cover plates and body wall of the case.

The means which we provide for interchangeably and quickly and accurately assembling the escapement units with the clock mechanism is also an important feature of the present invention, as well as the means for detachably looking the composite assembly to the mounting plate within the instrument case. While other specifically diiferent types of clock mechanisms might be employed, we have found that for best results in practical operation and the smooth and accurate control of the transmission of the drive to the chart at a predetermined rate, the construction and assembly of the invention as herein disclosed, is most desirable.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the 7 claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. Chart operating mechanism comprising spring and a casing therefor, a chart hub driven by said spring and projecting from the front of said casing, a plurality of spaced posts projecting from the rear of said casing, a separate escapement unit having means adapted to coact I with the respective posts to releasably mount the escapement unit in assembled relation upon the casing, releasable means coupling said escapement unit with the spring to control the rate of rotation of the chart hub, a mounting plate adapted to be secured to an instrument panel, and means on said plate adapted to coact with additional means on said posts to detachabl'y mount said escapement unit on said plate.

2. The chart operating mechanism defined in claim 1, wherein said plate also extends over the coacting means on said posts and said escapement unit so that separation of the plate and casing is necessary before the escapement unit can be separated from the casing.

3. In a chart hub drive, a spring motor casing having a chart mounting hub projecting from the front, a plurality of circumferentially spaced members projecting from the rear of said casing, an escapement unit releasably coupled to I said spring motor and detachably mounted between said members, and an instrument panel mounting plate yieldably secured upon said members rearwardly of and separately from said escapement unit mounting.

4. In the chart hub drive defined in claim 3, said means for yieldably securing the mounting plate on said members comprising apertures in said plate fitting over at least two of said members and a resilient snap fit connection between another one of said members and said plate.

5. In the chart hub drive defined in claim 4, said snap fit connection comprising a spring rod anchored at its ends to traverse one side of an aperture in said plate and a cooperating locking groove on the associated member.

6. In drive means for meter charts or the like comprising a motor having a casing and a control mechanism therefor contained in a separate casing and adapted to be operatively coupled to said motor; means for removably mounting said control mechanism externally on the motor casing comprising a plurality of fixed studs on one of said casings and means on the other of said casings interlocking with complementary means on said studs by relative movement of said casings to detachably support said control mechanism in coupled relation with said motor.

7. The invention as defined by claim 6, wherein said casing of the control mechanism is supported between said studs and the interlocking means comprises a plurality of spaced elements on said casing coacting with the complementary means on the respective studs.

8. The invention as defined by claim 7, in which each of said elements is a cam projecting from the periphery of said casing and effectively interlocked with means on said studs by rotative displacement of said casing relative to the motor casing.

JOHN B. MCGAY. GEORGE E. NICHOLSON.

References Cited in the file of this patent UNITED STATES PATENTS plumb er Name Date 230,262 Fitt July 20, 1880 1,389,953 Loebker M Sept. 6, 1921 1,874,967 Grcenleaf Aug. 30, 1932 1,909,073 Putnam May 16, 1933 2,102,268 Hoppenstand Dec. 14, 1937 2,161,207 Smith a June 6, 1939 2,393,671 Wolfe Jan. 29, 1945 2,497,079 Godley Feb. 14, 1950 2,531,133 Lehde Nov. 21, 1950 2,543,032 Laviana Feb. 27, 1951 FOREIGN PATENTS Number Country Date 502,153 Germany July 11, 1930 720,656 France Dec. 4, 1931 

